Processing flow behavior and modeling of polyethylene melts

Abstract

This paper presents experimental observations and numerical simulations of six polyethylene melts with different molecular structures in the planar flow with a confined slit. The polyethylene melts investigated include three low-density polyethylene grades (LDPE), two high density polyethylene grades (HDPE), and one linear low density polyethylene (LLDPE). The objectives are to reveal the differences in the rheological and processing flow properties of these polyethylene melts, and correlate those properties with their molecular structures. Through this study, the author would also like to present a successful approach using simple shear data, in terms of a Wagner integral constitutive equation, to predict processing flow behaviors of polymer melts at a reasonable accuracy.

Keywords

extrusion / planar entry flow / rheological characterization / numerical simulation / die swell / polyethylene melt / polyflow / Wagner integral equation

References

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[2] WagnerM. H.. Analysis of time-dependent nonlinear stress-growth data for shear and elongational flow of a low density branched polyethylene melt[J]. Rheol Acta, 1976, 15: 136-142